Improvements in three-dimensional accelerometers have been instrumental in increasing the acceptance of personal activity tracking devices. Personal activity tracking devices can measure movement of the wearer and are able to detect and record physical activity such as walking, running and exercising. Personal activity tracking devices also may be equipped with connection means including but not limited to Bluetooth, Ethernet, USB, WiFi, and IrDA, used to connect with a mobile phone running application software, a server connected with the cloud or a vehicle computing system. A wrist mounted wearable device or personal activity tracking device allows for detection of wrist movement.